How to use Blender Filmic in After Effects?
Video tutorial explaining how to do it. 

To get it to work in After Effects you need to make a copy of Blender's config.ocio file. Open it up in text editor and add a line of code.

Find this in your text editor:

CIE XYZ color space
XYZ: XYZ

Delete that and add what is below.

# CIE XYZ color space #XYZ: XYZ
# XYZ: XYZ

# Need a general default
default: Linear


Save the text file and you are done. Brendan Bolles fixed it the creator of the openColorIO plugin for After Effects.

Video tutorial explaining how to do it.